Rate of Flow

With many departments looking for new and improved ways to find equipment to help them do their jobs, many departments have changed nozzles.

There has often been a long debate about solid stream nozzles, combination nozzles, and automatic nozzles.

I am a strong supporter of solid stream nozzles which is clearly a change in position for me as I was long a proponent of combination.

Nozzle technology has become very advanced and there are many new advances that have been made except one....the human factor.

It has been my experience that while many of the new nozzles have the capability of greater flows, I have often asked the question of what pump pressure is being used, and often I find that the pump operator is pumping an inadequate pressure to provide the flows that are capable of being flowed.

This is simple...measure and discharge the nozzle into a container of known volume or from a container of known volume...like your water tank.

Do some experiments with different nozzles and different flows and time them so you can determine how long in minutes does it take to empty our 500 gallon tank or 750 or whatever size. If you use portable folding tanks how long does it take to fill a certain volume bag? Use 55 gallon drums if you have to...any container of a known volume for a certain period of time.

My guess is that if you tell your pump operator to just charge a preconnected line with a certain nozzle type on it, using the manpower you would normally have at a fire, you will get a pump pressure much lower than what you should have, thus resulting in a much lower flow. The automatic nozzle will present a great looking stream regardless of pressure so you will not be able to tell.

I believe you will find that your new sophisticated nozzle will be flowing about 100 to 125 GPM not much better than a 20 year old turbojet nozzle!

This bulletin is really not about nozzles but about rate of flow. I really don't care about your nozzle preference, combination, solid, automatic or what, but don't believe you are flowing enough water when in fact you are not.

The pump operator needs to be trained and there needs to be sufficient number of personnel to handle higher pressures for higher flows...it's that simple.

You can fool the firefighters, the pump, and the nozzle, but you can't fool the fire! The minute you begin to apply the correct rate of flow the fire will darken and go out. It is a seesaw that never balances, you are either winning or losing, there is no such thing as holding a fire.

Practice, you might be surprised at what you find out.